1. Field of the Invention
The invention relates to an embroidery data processing system for producing embroidery data necessary for embroidering a pattern of stitches in an embroidering area by a sewing machine and, more particularly, to improvements in producing proper embroidery data in respect of connection with the shape of a desired embroidering area.
2. Description of the Related Art
Embroidery data processing systems capable of automatically producing embroidery data necessary for embroidering a pattern of stitches in a desired embroidery area by a sewing machine on the basis of contour data representing the contour of the desired embroidery area have been proposed in U.S. Pat. No. 4,982,674 granted to the applicant of the present patent application, Japanese Patent Laid-open No. Hei 3-128084 filed by the applicant of the present patent application and Japanese Patent Publication No. Sho 62-2556.
The embroidery data processing system disclosed in U.S. Pat. No. 4,982,674 produces embroidery data taking into consideration a stitching direction specified by the operator, on the basis of data of the continuous contour of an embroidery area entered by the operator and the stitching direction specified by the operator. However, it is impossible to produce embroidery data for stitching stitches in all directions that are perfectly suitable for the shape of the embroidering area, because only one stitching direction can be specified.
The embroidery data processing system proposed in Japanese Patent Laid-open No. Hei 3-128084 divides the contour of an embroidering area, represented by data entered by the operator, into two opposite partial contours with respect to a direction perpendicular to an embroidering direction, estimates the direction of extension of the center line of the embroidering area from the shapes of the partial contours, divides the embroidering area into a plurality of blocks arranged in a line along the direction of extension of the center line, and produces embroidery data taking into consideration the respective shapes of the blocks. Accordingly, this embroidery data processing system is capable of automatically determining different stitching directions respectively for the blocks. Therefore, the direction of stitches formed according to the embroidery data produced by this embroidery data processing system is more suitable for the shape of the embroidering area than that of stitches formed according to the embroidery data produced by the embroidery data processing system disclosed in U.S. Pat. No. 4,982,674. However, the stitching direction determined by the embroidery data processing system does not always coincide perfectly with that desired by the operator and, since the embroidery data is produced only on the basis of the data representing the contour of the embroidering area, the embroidery data is not perfectly proper in respect of connection with the shape of the embroidering area.
The embroidery data processing system disclosed in Japanese Patent Publication No. Sho 62-2556 produces embroidery data taking into consideration a desired stitching direction when data representing the contours of a plurality of blocks of an embroidering area is entered and a desired stitching direction is specified for each block. Accordingly, different stitching directions corresponding to those desired by the operator are determined respectively for the blocks of the embroidering area. Therefore, stitches are formed in directions more appropriate for the shape of the embroidering area than those determined by the foregoing embroidery processing systems. However, this embroidery data processing system requires data individually representing the plurality of blocks of the embroidering area, and data representing stitching directions respectively for the plurality of blocks even if the desired stitching directions for the adjacent blocks are the same, which increases the instructional load on the operator